The invention relates to a power steering system with hydraulic power assistance, in particular for motor vehicles, having a pressure medium pump for producing a hydraulic pressure.
A generic power steering system is known from DE 198 29 531 A1.
Furthermore, reference is made to DE 197 52 397 A1 for the further prior art.
The generic document shows a power steering system with hydraulic power assistance for motor vehicles, a steering spindle which is provided with a steering handle being connected to an input element of a steering mechanism. An output element of the steering mechanism is connected to wheels, to be steered, of the motor vehicle. Pressure medium is applied to two working spaces of a servomotor of a power assistance device by a booster pump via a steering valve in a manner corresponding to a prevailing torque in the region of the steering spindle/input element. The booster pump or the pressure medium pump is driven hereby the internal combustion engine.
According to the generic document, two sensors for sensing a rotary angle and a torque are arranged on the steering spindle or on the output element of the steering mechanism. Both the magnitude and the direction of the hydraulic power assistance and the centering of the wheels to be steered are controlled via a common, electronically controlled solenoid valve. There is a torque sensor to sense the steering force.
The generic power steering system represents a development of the previously disclosed power steering systems, as disclosed, for example, in EP 0 440 638 B1.
Power assistance using simple means is possible as a result of the generic power steering system. Furthermore, the steering precision is improved.